Camera with an exposure control function

ABSTRACT

A camera according to this invention includes a backlight judgment section which determines whether the photographic scene is against light by comparing the average luminance of the entire photographic screen obtained by photometry with the luminance of the main subject at a distance-measuring point selected by distance measurement. With the backlight judgment section, the camera performs suitable exposure control accompanied by illumination, such as supplementary light, at the time of exposure in a photographic scene where the main subject is against light.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based upon and claims the benefit of priorityfrom the prior Japanese Patent Applications No. 2002-268732, filed Sep.13, 2002; No. 2002-271816, filed Sep. 18, 2002; and No. 2002-321314,filed Nov. 5, 2002, the entire contents of all of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates to a camera which performs correctexposure control by determining whether the subject is against light atthe time of measuring the brightness of the subject, and also to atechnique of processing image data in cameras.

[0004] 2. Description of the Related Art

[0005] In a scene where the main subject is photographed against lightor backlit as when there is a light source, such as the sun, behind themain subject, the shady part of the main subject is photographed, withthe result that the main subject collapses in black.

[0006] To prevent this, the shady part of the main subject is lighted bythe reflected light from a reflecting plate or illuminating light.Alternatively, when a picture is taken, strobe light is caused to emitlight, that is, daylight synchronized flash is done.

[0007] In making a decision on backlighting, if the area occupied by themain subject is large for the photographic screen, it is easy to make adecision. However, in a photographic scene where the area occupied bythe main subject is small, the luminance difference becomes smaller,which can cause a case where it cannot be determined that the subject isagainst light. To overcome this problem, for example, Jpn. Pat. No.2934712 has disclosed an exposure control method of additionallyproviding a focal point detecting section (distance measuring section)to the photometric section for measuring the brightness in the middle ofand the periphery of the photographic screen.

[0008] In the invention of Jpn. Pat. No. 2934712, the backlit state ofthe main subject is detected with a distance-measuring sensor. Forexample, in a photographic scene as shown in FIG. 3, the distancemeasuring sensor sets only region 33 b as the distance measuring rangein the area of the photographic screen 34T.

[0009] Furthermore, concerning a method of preventing improper exposurein a backlit photographic scene, a related technique has been disclosedin, for example, Jpn. Pat. Appln. KOKOKU Publication No. 7-27151. Inthis method, a camera capable of measuring the brightness and distancein a plurality of areas on the photographic screen selects one of theareas on the basis of the distance-measuring data. The photometric valuein the selected area is compared with the maximum one of the photometricdata in the other areas, thereby making a decision on backlighting. Whenit is determined that the photographic scene at that time is againstlight, daylight synchronized flash has been done.

[0010] Moreover, in a digital camera, when a backlit scene is notsubjected to a suitable image process, the resulting image is unnaturaland unattractive. For instance, the contour of the main subject deformsdue to the spread of light, which makes it difficult to reproduce anatural image.

[0011] To overcome this problem, for example, Jpn. Pat. Appln. KOKAIPublication No. 8-107519 or Jpn. Pat. Appln. KOKAI Publication No.11-32236 has disclosed the technique for analyzing the luminancedistribution of the image data obtained by the imaging element by use ofa histogram or the like to detect backlighting and changing the imageprocessing method. Those techniques are for balancing the brightness ofthe main subject with the brightness of the background, making use ofthe photographed images.

BRIEF SUMMARY OF THE INVENTION

[0012] According to an aspect of the present invention, there isprovided a camera comprising: a sensor array which detects an imagesignal of a subject existing in a specific position on a photographicscreen and has a plurality of sensors; a computing section whichcalculates the average value of the outputs of a part of the pluralityof sensors in the sensor array; an average photometric sensor whichdetects the average brightness at the photographic screen; an averageluminance computing section which calculates the average luminance valueat the photographic screen on the basis of the output of the averagephotometric sensor; and a subject state judgment section whichdetermines the state of the subject by comparing the average value ofthe sensor outputs with the average luminance value and a judgmentsection which determines exposure control during photographing on thebasis of the average luminance value and the results of thedeterminations at the subject state judgment section.

[0013] According to another aspect of the present invention, there isprovided a camera comprising: a sensor array which detects an imagesignal of a subject existing in a specific position on a photographicscreen and has a plurality of sensors; a computing section whichcalculates the average value of the outputs of a part of the pluralityof sensors in the sensor array; an average photometric sensor whichdetects the average brightness of visible light at the photographicscreen; an average luminance computing section which calculates theaverage luminance value at the photographic screen on the basis of theoutput of the average photometric sensor; an infrared photometric sensorwhich detects an infrared luminance value indicating the brightness ofthe average infrared light at the photographic screen; a subject statejudgment section which determines the state of the subject by comparingthe average value of the sensor outputs with the average luminancevalue; a subject field state judgment section which determines the stateof a subject field including the subject by comparing the averageluminance value with the infrared luminance value; and an exposurecontrol determining section which determines exposure control duringphotographing on the basis of the average luminance value and theresults of the determinations at the subject state judgment section andthe subject field state judgment section.

[0014] According to still another aspect of the present invention, thereis provided a camera comprising: a photometric section which measuresthe subject luminance in a plurality of areas on a photographic screen;a distance-measuring section which measures the subject distance in aplurality of areas on the photographic screen; a first select sectionwhich selects one from a plurality of distance-measuring areas on thephotographic screen on the basis of the distance-measuring data abouteach distance-measuring area; a second select section which selects onefrom the photometric area corresponding to the distance-measuring areaselected by the first select section and its adjacent photometric areason the basis of the photometric data about each photometric area; and abacklight judgment section which makes a decision on backlighting bycomparing the photometric data about the photometric area selected bythe second select section with the photometric data about eachphotometric area.

[0015] According to still another aspect of the present invention, thereis provided a camera comprising: an imaging section which detects asubject image signal; a backlighting state judgment section whichdetermines whether the subject is against light; a strobe unit whichemits strobe light onto the subject on the basis of the result of thedecision on backlighting at the backlighting state judgment section; andan image processing section which compares the brightness of the subjectwith that of the background when the strobe unit emits the strobe lightonto the subject, changes the amount of correction by a gamma conversionprocess or a contour emphasizing process on the basis of the result ofthe comparison, and processes the image of the subject image signaldetected by the imaging section.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0016]FIG. 1 shows a schematic configuration of the exposure controlsystem of a camera related to a first to a third embodiment of thepresent invention;

[0017]FIG. 2 shows a concrete configuration provided on the camera ofthe first embodiment;

[0018]FIG. 3 shows the relationship between the photographing area andthe distance-measuring area on the photographic screen;

[0019]FIGS. 4A, 4B, 4C, and 4D show the arrangement ofdistance-measuring points (areas) and light-receiving example ofobtained image data;

[0020]FIG. 5 is a flowchart to help explain exposure control in thefirst embodiment;

[0021]FIGS. 6A and 6B are flowcharts to help explain a firstmodification of the first embodiment;

[0022]FIGS. 7A and 7B are flowcharts to help explain a secondmodification of the first embodiment;

[0023]FIG. 8 is a diagram to help explain the relationship between thevisible light luminance and the infrared high luminance in the firstmodification;

[0024]FIG. 9 shows a concrete configuration provided on the camera ofthe second embodiment;

[0025]FIGS. 10A, 10B, 10C, and 10D show an outward appearance and a partof the inside of the camera in the second embodiment;

[0026]FIG. 11 is a flowchart to help explain exposure control in thesecond embodiment;

[0027]FIG. 12 is a diagram to help explain the relationship between thepixel area of the imaging element and the distance-measuring area(point) of the AF sensor;

[0028]FIGS. 13A and 13B show concrete configurations provided on thecamera of the third embodiment;

[0029]FIG. 14 is a block diagram of the main part of a camera with aphotometric function according to a fourth to a seventh embodiment ofthe present invention;

[0030]FIG. 15 schematically shows a configuration of the photometricsection related to the fourth to sixth embodiments;

[0031]FIG. 16 schematically shows a configuration of thedistance-measuring section related to the fourth to sixth embodiments;

[0032]FIG. 17 shows the relationship between the photometric area andthe distance-measuring area in the fourth embodiment;

[0033]FIG. 18 shows the relationship between the photometric area andthe distance-measuring area in the fifth embodiment;

[0034]FIG. 19 is a flowchart to help explain the release sequence of acamera provided with the photometric device related to the fourth tosixth embodiments;

[0035]FIG. 20 is a flowchart to help explain a decision on backlightingin the fourth embodiment;

[0036]FIG. 21 is a flowchart to help explain a decision on backlightingin the fifth embodiment;

[0037]FIG. 22 is a flowchart to help explain a decision on backlightingin the sixth embodiment;

[0038]FIG. 23 schematically shows a configuration of the photometric anddistance-measuring section in the seventh embodiment;

[0039]FIG. 24 is a block diagram of a camera according to an eighthembodiment of the present invention;

[0040]FIG. 25 is a diagram to help explain the sensor array and themonitoring range of the imaging section;

[0041]FIG. 26A shows an example of a backlit scene, FIG. 26B is adistribution diagram of brightness in the photographic scene of FIG.26A, FIG. 26C shows an example of the photographic scene after strobelight is emitted onto the photographic scene of FIG. 26A, FIG. 26D is adistribution diagram of brightness in the scene of FIG. 26C, FIG. 26Eshows a photographic scene when strobe light has not reached thesubject, and FIG. 26F is a distribution diagram of brightness in thephotographic scene of FIG. 26E;

[0042]FIG. 27A is a histogram of brightness when the γ value is normal,FIG. 27B is a histogram of brightness when the γ value is made smaller,FIG. 27C is a histogram of brightness after the emission of strobelight, and FIG. 27D is a histogram of brightness when the γ value ismade larger when strobe light has not reached the subject;

[0043]FIG. 28 is a distribution diagram of brightness when thephotographic scene is not against light;

[0044]FIG. 29 is an explanatory diagram about a γ conversion process;

[0045]FIG. 30A shows a functional configuration of the contouremphasizing section and FIG. 30B is a diagram to help explain contouremphasizing calculation;

[0046]FIGS. 31A and 31B are flowcharts to help explain the sequence ofphotographing control of the camera related to the eighth embodiment;

[0047]FIG. 32 is a diagram to help explain the assimilation of aperson's hair and the background in the γ conversion process;

[0048]FIG. 33 is a flowchart to help explain the sequence ofphotographing control of a camera related to a ninth embodiment of thepresent invention;

[0049]FIG. 34A is a positional distribution diagram of the amount ofintegration outputted from the imaging section before the emission ofstrobe light, FIG. 34B is a positional distribution diagram of theamount of integration outputted from the imaging section when sufficientstrobe light has not been emitted onto the main subject, and FIG. 34C isa positional distribution diagram of the amount of integration outputtedfrom the imaging section when sufficient strobe light has been emittedonto the main subject;

[0050]FIG. 35 is a flowchart to help explain the control sequence ofbacklight photographing with a camera related to a tenth embodiment ofthe present invention;

[0051]FIG. 36A shows a change in the amount of integration with respectto time of the background subject after the emission of strobe light andFIG. 36B shows a change in the amount of integration with respect totime of the main subject when sufficient strobe light has been emittedonto the main subject after the emission of strobe light;

[0052]FIG. 37A shows a change in the amount of integration with respectto time of the background subject after the emission of strobe light andFIG. 37B shows a change in the amount of integration with respect totime of the main subject when sufficient strobe light has not beenemitted onto the main subject after the emission of strobe light; and

[0053]FIG. 38A is a positional distribution diagram of brightness whenthe brightness difference between the person and the background issmall, FIG. 38B is a diagram to help explain the γ conversion process inFIG. 38A, FIG. 38C is a positional distribution diagram of brightnesswhen the brightness difference between the person and the background islarge, and FIG. 38D is a diagram to help explain the γ conversionprocess in FIG. 38C.

DETAILED DESCRIPTION OF THE INVENTION

[0054] Hereinafter, referring to the accompanying drawings, embodimentsof the present invention will be explained.

[0055] The basic idea of making a decision on backlighting with theexposure control system of a camera related to the first embodiment ofthe present invention will be explained by reference to FIG. 1.

[0056] The exposure control system includes the component partsexplained below.

[0057] The exposure control system includes a photometric sensor (AEsensor) 1 for determining the luminance (photometric value) in visiblelight on the entire photographic screen, an average luminance computingsection 2 for determining the average luminance of the entire screenfrom the obtained photometric value, a distance-measuring sensor 3 forperforming a distance-measuring operation on a plurality ofdistance-measuring points on the photographic screen, and a distancecomputing section 4 for determining the distance to the subject from thedistance-measuring data obtained in the distance-measuring operation.The exposure control system further includes a subject select section 5for setting, for example, the one existing at the closest distance asthe main subject from the results of measuring the distance andselecting the position of the main subject as a distance-measuring point(hereinafter, referred to as a point) on the photographic screen. Theexposure control system further includes a luminance computing section 6for computing the quantity (luminance) of light entering the selectedpoint, a backlight judgment section 7 for determining the state of thesubject from the luminance of the selected point and the averageluminance, a strobe light emission section 8 for emitting supplementarylight during backlighting, an infrared photometric sensor 52 forreceiving by remote control and determining the luminance of infraredlight of the entire photographic screen, an artificial light judgmentsection 53 for determining the state of the field including theluminance of the infrared light and the average luminance, a modediscriminative section 56 for discriminating the present photographicmode set by a mode change section 55 explained later, and a controlsection 9 for determining exposure control in photography includingstrobe light emission control.

[0058] The light-receiving face of the photometric sensor 1 is separatedinto a peripheral photometric section la and the central photometricsection 1 b. In the embodiment, the backlight judgment section 7 servingas subject state decision means determines whether the subject isagainst light or backlit. The artificial light judgment section 53serving as subject field state decision means determines whether thelight source of the subject field is artificial.

[0059] The exposure control system further includes a photometricbacklight judgment section 10 for making a decision on backlighting bycomparing the individual outputs of the divided photometric sensorsections. The decision on backlighting is effective when the mainsubject exists in the middle of the photographic scene. The artificiallight judgment section 53, which determines whether the light source isof natural light or artificial light (for example, incandescent lamplight or fluorescent lamp light), compares the output of the infraredphotometric sensor 52 with the output of the average luminance computingsection 2. When the subject 27 exists under artificial light, theartificial light judgment section 53 serves to prevent color seepage byartificial light (for example, green seepage under fluorescent lamplight).

[0060] When the exposure control system is actually constructed of theaverage luminance computing section 2, distance computing section 4,subject select section 5, luminance computing section 6, backlightjudgment section 7, control section 9, photometric backlight judgmentsection 10, and artificial light judgment section 53, the control andcomputing processes are realized by a single microcomputer (CPU).

[0061] In the exposure control system, the exposure operation is startedby the turning on of the release switch or the like of the camera (notshown). First, the photometric sensor 1 and infrared photometric sensor52 measure brightness. From the resulting photometric values, theaverage luminance computing section 2 determines the average luminanceof visible light and the luminance of infrared light on the entirescreen.

[0062] Next, the distance-measuring sensor 3 measures the distance toeach of the points on the photographic screen one after another. Usingthe resulting distance-measuring data, the distance computing section 4determines the distance to the subject at each point. The subject selectsection 5 determines the closest one of the subject distances at theindividual points to be the point where the main subject is present andselects the point as a point to be focused on. The luminance computingsection 6 monitors and finds the luminance of the selected point.

[0063] Next, the backlight judgment section 7 compares the averageluminance of the entire screen with the luminance of the selected point,thereby determining whether the photographic scene is against light. Ifthe average luminance of the entire screen is higher than the luminanceof the selected point, the backlight judgment section 7 determines thatthe surroundings are brighter than the main subject, that is, the mainsubject is against light. Furthermore, the artificial light judgmentsection 53 compares the luminance of infrared light on the entire screenwith the luminance of visible light at the average luminance computingsection 2, thereby determining whether the subject is in artificiallight. To photograph a scene against light and a scene illuminated withartificial light, strobe light is emitted according to the ISOsensitivity of the photographing medium (such as the imaging element orfilm), the aperture value, and the distance to the subject. In this way,a decision on backlighting is made on the basis of the brightness of theselected point (the position of the main subject) and the brightness ofthe entire screen and color seepage by artificial light is prevented,which enables proper exposure control. When the average luminance islower than the luminance of the point, it is determined that the mainsubject is not against light, with the result that exposure control isperformed suitably without emitting strobe light.

[0064]FIG. 2 shows a concrete configuration of the electronic circuitsystem of a camera as a first embodiment to which the exposure controlsystem of the present invention is applied. The camera of the firstembodiment is a digital camera that converts the subject image intoimage data with a photoelectric conversion element, carries out variousimage processes, and records the resulting data.

[0065] The camera is roughly composed of a photometricdistance-measuring system, an image pickup optical system, and animaging system. A calculation control section (CPU) 11, which controlsthe entire camera, is composed of a one-chip microcomputer or the like.

[0066] The photometric distance-measuring system includes adistance-measuring section 25 for measuring the distance to a subject27, an A/D conversion section 14 for A/D converting the subject imagesignal from the distance-measuring section 25 and outputting a digitalimage signal, split-type sensors 16 a, 16 b for receiving the lightgathered by an AE lens 15, and an AE circuit 17 which is composed of alogarithmic compression circuit and others and measures the brightnessof the inside of the photographic screen. The distance-measuring section25 is composed primarily of two light-receiving lenses 12 a, 12 bprovided the base length B away from each other, and a pair of sensorarrays 13 a, 13 b for receiving the subject image formed by the lenses12 a, 12 b and generating a subject image signal by photoelectricconversion.

[0067] The image pickup optical system is composed of a photographiclens (zoom lens) 18 for forming an image of the subject, a lens drivingmechanism (LD) 19 for driving the photographic lens 18 to bring thecamera into focus, and a zoom driving mechanism 24 for changing theangle of coverage by moving the lens barrel. The imaging system includesan imaging element (CCD) 20 for creating image data on the basis of theimage of the subject formed by the photographic lens 18, an imageprocessing section 21 for subjecting the image data obtained from theimaging element 20 to image processes, including γ conversion and imagecompression, and a recording section 22 for recording the image datasubjected to image processing.

[0068] The imaging system further includes a switch input section(release switch) 23 for starting a specific sequence in the calculationcontrol section 11 in response to the operation of the photographer, astrobe emitting section 26 for emitting supplementary illumination lightonto the subject 27, a strobe driving section 28 for performing drivingcontrol of the strobe emitting section 26, an infrared photometriccircuit 54 for receiving the signal from an infrared remote control anddetecting the infrared light component from the subject 27, and a modechanging section 55 for selectively setting the desired one of, forexample, the aperture-value priority mode, shutter-speed priority mode,strobe forced-emission mode, strobe OFF mode, spot photometric mode, andinfinite mode.

[0069] As for the component parts of the camera, only the membersrelated to the subject matter of the first embodiment of the presentinvention are described. Explanation of the other component parts anordinary camera has, such as the finder, will be omitted, because theyare supposed to be included.

[0070] The two light-receiving lenses 12 a, 12 b provided the baselength B apart gather light, which is then converted photoelectricallyby a pair of sensor arrays 13 a, 13 b and further A/D converted by A/Dconversion section 14. The A/D conversion section 14 produces a pair ofdigital image signals from a pair of analog signals produced by the pairof sensor arrays 13 a, 13 b. The CPU 11 compares the digital signals,thereby determining the relative positional difference x between theimage input positions.

[0071] Since the subject distance L, the focal length f of thelight-receiving lens, and the base length B vary in such a manner thatthey fulfill the equation x=B·f/L as shown in FIG. 2, detecting xenables the focusing distance L to be calculated. Since the sensorarrays are extended horizontally, when a photographic scene as shown inFIG. 3 is aimed at, the area 33 a is monitored. The area 33 a is dividedinto seven blocks as shown in FIG. 4A and the aforementioned detectionis carried out using the image signal of each block, which enables thedistance of seven points on the screen to be measured. Of the sevenresults of measurements, for example, the closest distance is determinedto be the main subject distance.

[0072] When the photographic lens 18 is a zoom lens, the angle of viewis turned to the telephoto side, which enables only the photographicarea 34T on the screen in the photographic scene shown in FIG. 3 to bephotographed. At this time, if the distance-measuring area continues tobe area 33 a, things outside the screen are also measured in distance.Therefore, in the telephoto mode, the distance-measuring area isnarrowed to area 33 b. As shown in FIG. 4B, multipoint AF (multi-AF) ofseven points in the seven narrowed areas is carried out. The AE circuit17 and sensor arrays 16 a, 16 b measure the brightness of visible lighton the entire screen. On the basis of the result of the measurement, theCPU 11 performs exposure control. In the sensor arrays 16 a, 16b, theoutput of the sensor array 16 a, or the area (in the telephoto mode) 32shown in FIG. 3, is selected in the telephoto mode according to a changein the angle of view caused by the zooming of the photographic lens. Inthe wide angle mode, the sum of the outputs of the sensor arrays 16 a,16 b, or the area (in the wide angle mode) 31 is selected and photometryis performed. Furthermore, the infrared photometric sensor 52 andinfrared photometric circuit 54 measure the luminous intensity ofinfrared light on the entire screen (photometric range 52R).

[0073] Each of the septsected distance-measuring points shown in FIGS.4A and 4B is composed of rectangular pixels arranged in a plurality ofcolumns. Since each pixel outputs data according to the shade of theimage, image data as shown in FIG. 4D is obtained. By averaging theimage data from the individual pixels, the average luminance of eachpoint is determined. Use of multi-AF enables the position of the mainsubject to be detected and further the luminance at the position to bedetermined, which makes it possible to photograph by exposure controlputting stress on the main subject, according to a flowchart shown inFIG. 5.

[0074] An example of using the photometric sensors anddistance-measuring sensors of the first embodiment will be explained byreference to a flowchart in FIG. 5.

[0075] First, the zoom position of the photographic lens 18 isdetermined (step S1). From the determined zoom position, it isdetermined whether the photographic lens 18 has been turned to the wideangle side (step S2). In this determination, if the lens 18 has beenturned to the wide angle side (YES), the angle of view 34W is set asshown in FIG. 3 and the photometric range 31 and distance-measuringrange 33 a are selected (step S3). On the other hand, if thephotographic lens 18 has been turned to the telephoto side, not to thewide angle side (NO), the angle of view 34T is set and the photometricrange 32 and distance-measuring range 33 b are selected (step S4).

[0076] Distance measuring is done in the distance-measuring rangeselected as described above (step S5). Of the results of themeasurements, the point (distance-measuring point) indicating theclosest distance where the main subject exists is set as the selectedpoint (step S6). The main subject average photometric value SP_(AVE)indicating the brightness of the image output at the selected point iscalculated (step S7). Then, the AE sensor selected in step S4 measuresthe luminous intensity in the photometric range (photographic screen)(step S8) and calculates the average photometric value BV_(AVE), theaverage of the outputs obtained in the photometry (step S9).

[0077] On the basis of the main subject distance obtained in step S6,the ISO sensitivity of photographing mediums (including the imagingelement and film), and information on the zoom position-obtained in stepS1, the guide number of the strobe unit is calculated and it isdetermined whether strobe light reaches the main subject (step S10). Ifit has been determined that the strobe light reaches the main subject(YES), it is determined whether the average photometric value BV_(AVE)is equal to or larger than a specific value BV_(O) (step S11). That is,the reliability of the obtained main subject average photometric valueSP_(AVE) is determined on the basis of the average photometric value.Since the output of the distance-measuring sensor does not pass throughthe logarithmic compression circuit, the linearity of photometry(dynamic range) is limited. In step S1, it is determined whether theaverage photometric value BV_(AVE) is equal to or larger than thespecific value BV_(O).

[0078] In step S11, if the average photometric value BV_(AVE) is largerthan the specific value BV_(O) (YES), the main subject averagephotometric value SP_(AVE) is considered reliable. The main subjectaverage photometric value SP_(AVE) is compared with the averagephotometric value BV_(AVE), thereby determining whether the averagephotometric value BV_(AVE) is larger than the value SP_(AVE), that is,whether the subject is against light (step S12).

[0079] On the other hand, if it has been determined in step S10 thatstrobe light does not reach the main subject (NO), if it has beendetermined in step S11 that the average photometric value BV_(AVE) issmaller than the specific value BV_(O) (NO), or if it has beendetermined in step S12 that the average photometric value BV_(AVE) issmaller than the main subject average photometric value SP_(AVE) (NO),exposure control is performed on the basis of the average photometricvalue BV_(AVE), taking no account of the main subject averagephotometric value SP_(AVE) (step S13). Then, the sequence is completed.

[0080] On the other hand, if it has been determined in step S12 that theaverage photometric value BV_(AVE) is larger than the main subjectaverage photometric value SP_(AVE) (YES), or if it has been determinedthat the photographic scene is against light with the surroundingsbrighter than the main subject, or that the photographic scene needs theemission of strobe light, exposure is made with strobe light serving assupplementary light (step S14). Then, the sequence is completed.

[0081] As described above, with the first embodiment, the point forbringing the subject into focus on the photographic scene is caused tocoincide with the point for exposure adjustment and a decision onbacklighting is made by comparing the photometric values (luminances).Thus, the photographer has only to press the release button to make adecision on backlighting and make exposure suitable for the photographicscene. As a result, the photographer can take a picture in focus with agood exposure.

[0082] Since whether strobe light reaches the main subject properly istaken into account, it is possible to prevent the battery from beingconsumed due to a useless emission of strobe light.

[0083] As a first modification of the first embodiment which realizesexposure control putting stress on the main subject, an example of usingphotometric sensors, distance-measuring sensors, and infraredphotometric sensors will be explained by reference to a flowchart shownin FIG. 6. Because step S21 to step S27 in the first modification arethe same as step S1 to step S7 in the aforementioned flowchart, theywill be explained briefly.

[0084] First, the zoom position of the photographic lens 18 isdetermined. From the zoom position, it is determined whether thephotographic lens 18 is on the wide angle side. If the photographic lens18 has been turned to the wide angle side, the angle of view 34W is setas shown in FIG. 3 and the photometric range 31 and distance-measuringrange 33 a are selected. On the other hand, if the lens 18 has not beenturned to the wide angle side, the angle of view 34T is set and thephotometric range 32 and distance-measuring range 33 b are selected(step S21 to step S24). Distance measuring is done in these selecteddistance-measuring ranges. Of the results of the measurements, the point(distance-measuring point) indicating the closest distance where themain subject exists is set as the selected point. The main subjectaverage photometric value SP_(AVE) indicating the brightness of theimage output at the selected point is calculated (step S25 to step S27).

[0085] Then, the photometric sensor (AE sensor) 1 selected in steps S23,S24 measures the luminous intensity of visible light in the photometricrange and the infrared photometric sensor 52 measures the luminousintensity of infrared light (step S28). Then, the average photometricvalue BV_(AVE), the average of the outputs obtained at the photometricsensor 1, is calculated (step S29). In addition, the infraredphotometric value BVr obtained at the infrared photometric sensor 52 iscalculated (step S30).

[0086] Then, it is determined whether the camera photographic mode setby the mode changing section 55 is the strobe OFF mode to inhibit theemission of strobe light, the infinite mode to photograph the subject inthe distance, or the spot photometric mode to measure the luminousintensity only in the central part of the screen (step S31). In thisdetermination, if any one of the modes has been set (YES), controlproceeds to step S37 explained later. On the other hand, if none of themodes has been set (NO), the guide number of the strobe unit iscalculated on the basis of the main subject distance, the ISOsensitivity of photographing mediums (including the imaging element andfilm), and information on the zoom position obtained in step S21. Then,it is determined whether strobe light reaches the main subject (stepS32).

[0087] In step S32, if it has been determined that strobe light does notreach the main subject (NO), control goes to step S37 explained later.On the other hand, if it has been determined in step S32 that strobelight reaches the main subject (YES), it is determined whetherartificial light has been detected, on the basis of the averagephotometric value BV_(AVE) of visible light and the infrared photometricvalue BVr (step S33).

[0088] As shown in the relationship between the visible light luminanceand the infrared light luminance (wide ISO 100) of FIG. 8, ifBV_(AVE)<visible light luminance Lv13 and BV_(AVE)>BVr+3.5 (Lv), it isdetermined that light is emitted from a fluorescent lamp, whereas ifBV_(AVE)<Lv13 and BV_(AVE)<BVr, it is determined that light is emittedfrom an incandescent lamp. If such artificial light has been detected(YES), control proceeds to step S38 explained later, where exposureaccompanied by the emission of strobe light is made. On the other hand,if artificial light has not been detected (NO), it is determined thatthere is no color seepage. Then, it is determined whether the subjecthas a low luminance in visible light (step S34). This determination ismade, using BV_(AVE)<Lv 10 as a decision criterion as show in FIG. 8. Inthe determination, if the subject has a low luminance (YES), controlgoes to step S38. If the subject has not a low luminance (NO), it isdetermined whether the average photometric value BV_(AVE) is equal to orlarger than a specific value BV_(O) (step S35). A decision on thereliability of the obtained main subject average photometric valueSP_(AVE) is made on the basis of the average photometric value.Specifically, since the output of the distance-measuring sensor does notpass through the logarithmic compression circuit, the linearity (dynamicrange) of photometry is limited. Thus, in step S35, it is determinedwhether the average photometric value BV_(AVE) is equal to or largerthan the specific value BV_(O).

[0089] In step S35, if it has been determined that the averagePhotometric value BV_(AVE) is larger than the specific value BV_(O)(YES), the main subject average photometric value SP_(AVE) is consideredreliable. The main subject average photometric value SP_(AVE) iscompared with the average photometric value BV_(AVE), therebydetermining whether the average photometric value BV_(AVE) is largerthan the value SP_(AVE), that is, whether the subject is against light(step S36).

[0090] If it has been determined in step S31 that the photographic modeis any one of the strobe OFF mode, infinite mode, and spot photometricmode (YES), if it has been determined in step S32 that strobe light doesnot reach the main subject (NO), if it has been determined in step S35that the average photometric value BV_(AVE) is smaller than the specificvalue BV_(O) (NO), or if it has been determined in step S36 that theaverage photometric value BV_(AVE) is smaller than the main subjectaverage photometric value SP_(AVE) (NO), exposure control is performedon the basis of the average photometric value BV_(AVE), taking noaccount of the main subject average photometric value SP_(AVE) (stepS37). Then, the sequence is completed.

[0091] On the other hand, if it has been determined in step S33 thatartificial light has been detected (YES), it has been determined in stepS34 that the main subject has a low luminance (YES), or if it has beendetermined in step S36 that the average photometric value BV_(AVE) islarger than the main subject average photometric value SP_(AVE) (YES),that is, it has been determined that the photographic scene is againstlight with the surroundings brighter than the main subject, or that thephotographic scene needs the emission of strobe light, exposure is madewith strobe light serving as supplementary light (step S38). Then, thesequence is completed.

[0092] As described above, the first modification not only produces thesame effect of the first embodiment but also prevents the occurrence ofcolor seepage because of the emission of strobe light taking colorseepage into account on the basis of a decision on artificial light.This makes it easier to take a picture of a natural shade in properfocus with adjusted exposure.

[0093] Furthermore, a second modification of the first embodiment willbe explained by reference to a flowchart shown in FIG. 7. The secondmodification is such that the sequence of the distance-measuring stepand the photometric step in the first modification is reversed and thestep of determining whether strobe light reaches the subject is omitted.In the second modification, the same steps as those in the firstmodification are indicated by the same reference numerals and will beexplained briefly. Step S39 to step S41 in the second modificationcorrespond to step S28 to step S30 in the first modification. Step S42to S44 in the second modification correspond to step S25 to step S27 inthe first modification.

[0094] First, the zoom position of the photographic lens 18 isdetermined. From the zoom position, it is determined whether thephotographic lens 18 is on the wide angle side. If the photographic lens18 has been turned to the wide angle side, the angle of view 34W is setas shown in FIG. 3 and the photometric range 31 and distance-measuringrange 33 a are selected. On the other hand, if the lens 18 has not beenturned to the wide angle side, the angle of view 34T is set and thephotometric range 32 and distance-measuring range 33 b are selected(step S21 to step S24).

[0095] Then, the photometric sensor (AE sensor) 1 selected in steps S23,S24 measures the luminous intensity of visible light in the photometricrange and the infrared photometric sensor 52 measures the luminousintensity of infrared light. Then, the average photometric valueBV_(AVE), the average of the outputs obtained at the photometric sensor1, is calculated. In addition, the infrared photometric value BVrobtained at the infrared photometric sensor 52 is calculated (step S39to step S41).

[0096] Then, distance measuring is done in the selecteddistance-measuring range 33 a or 33 b. Of the results of themeasurements, the point (distance-measuring point) indicating theclosest distance where the main subject exists is set as the selectedpoint. The main subject average photometric value SP_(AVE) indicatingthe brightness of the image output at the selected point is calculated(step S42 to step S44).

[0097] If it has been determined in step S31 that any one of the strobeOFF mode, infinite mode, and spot photometry mode has been set (YES), ifit has been determined in step S32 that strobe light does not reach themain subject (NO), if it has been determined in step S35 that theaverage photometric value BV_(AVE) is smaller than the specific valueBV_(O) (NO), or if it has been determined in step S36 that the averagephotometric value BV_(AVE) is smaller than the main subject averagephotometric value SP_(AVE) (NO), meaning that the subject is not againstlight, exposure control is performed on the basis of the averagephotometric value BV_(AVE), taking no account of the main subjectaverage photometric value SP_(AVE) (step S37). Then, the sequence iscompleted.

[0098] On the other hand, if it has been determined in step S33 thatartificial light has been detected (YES), it has been determined in stepS34 that the main subject has a low luminance (YES), or if it has beendetermined in step S36 that the average photometric value BV_(AVE) islarger than the main subject-average photometric value SP_(AVE) (YES),that is, it has been determined that the photographic scene is againstlight with the surroundings brighter than the main subject, or that thephotographic scene needs the emission of strobe light, exposure is madewith strobe light serving as supplementary light (step S38). Then, thesequence is completed.

[0099] In the second modification, the distance can be measured, takinginto account the results of measurements by the photometric sensors.Therefore, it is possible to take a picture in accurate focus withproper exposure without being influenced by the luminance.

[0100] A second embodiment of the present invention will be explained.

[0101]FIG. 9 shows a conceptual configuration of a camera related to thesecond embodiment. In the second embodiment, the like component parts asthose of FIG. 2 are indicated by the same reference numerals andexplanation of them will be omitted. While the distance-measuringsection 25 of the first embodiment requires a pair of light-receivinglenses 12 a, 12 b and a pair of sensor arrays 13 a, 13 c, adistance-measuring section 40 of the second embodiment uses alight-receiving lens 41, a sensor array (external array sensor) 42, aphotographic lens 18, and an imaging element 20 to make trigonometricdistance measurements.

[0102] Trigonometric distance measurements are made as follows. Thephotographic lens 18 is set in a specific position. It is determined inwhich part of the sensor array 42 the same image as the image dataobtained in the central part of the screen of the CCD 20 can bedetected. From the result of the determination, the subject distance Lis found on the principle of trigonometric distance measurements. Ofcourse, use of the image data in the part deviating from the centralpart of the screen enables the distance of the main subject not existingin the middle of the screen to be measured as shown in FIG. 3. In thiscase, the sensor array 42 is composed of a plurality of columns ofsensor arrays as shown in FIG. 10B. FIG. 10A shows an outward appearanceof and a part of the inside of a camera 51 provided with thedistance-measuring section of the second embodiment.

[0103] In the camera 51, the photographic lens 18 is provided almost inthe center of the camera front. Above the photographic lens 18, thelight-receiving lens 41 and strobe emitting section 26 are provided sideby side. On the top of the camera, the release switch 23 is provided.Inside the camera, the imaging element 20 is provided behind thephotographic lens 18 and the sensor array 42 is provided behind thelight-receiving lens 41.

[0104] The sensor array 42 is composed of, for example, three linesensors arranged side by side as shown in FIG. 10B to measure thedistance of the main subject shifted laterally from the center of thephotographic screen. A lateral arrangement of sensor arrays 42 withrespect to the photographic screen 50 as shown in FIG. 10C makes itpossible to monitor the main subject moved sideways (42L) or standingaside as shown in FIG. 10D.

[0105] Accordingly, with the second embodiment, a space corresponding toone light-receiving lens and the cost of one sensor array can be saved.The light-receiving lens and the photographic lens can be provided witha wider space between them, with the result that the base length Bbecomes longer and therefore higher accuracy can be realized.

[0106] Referring to a flowchart shown in FIG. 11, exposure control inthe camera of the second embodiment will be explained.

[0107] First, information on the zoom position of the photographic lens18 is determined. On the basis of the information about the zoomposition, the focus position of the photographic lens 18 is set to aspecific position (step S51). The position setting makes therelationship between the photographic lens 18 and the imaging element 20almost equal to the relationship between the light-receiving lens 41 andthe sensor array 42. This is done to increase the distance-measuringaccuracy by making the focus position of the photographic lens 18 almostequal to that of the light-receiving lens 41. In the setting, one pixelof the sensor array 42 does not correspond to one pixel of the imagingelement 20 in a one-to-one ratio. To overcome this problem, all of theoutputs of ten pixels, 2×5, of the imaging element 20 are added andcaused to correspond to one pixel of distance-measuring image data (stepS52). The addition matches the distance-measuring range (output) of thesensor array 42 with that of the imaging element 20.

[0108] Next, multi-AF is performed by trigonometric distancemeasurements (step S53). From the obtained distance-measuring data, theposition of the main subject is detected (the point is selected) (stepS54). Then, focusing is done so as to meet the position of the mainsubject or the distance to the selected point (step S55). During thefocusing, the output of the imaging element 20 is monitored and a fineadjustment of the position of the photographic lens 18 is made so thatthe contrast of the image formed on the light-receiving surface of theimaging element 20 may be optimum.

[0109] Next, the exposure value is determined from the output of all ofthe imaging element 20 (step S56). Next, using the AF sensor, thedistance-measuring value of only the position of the main subject iscalculated (step S57). For example, in a photographic scene as shown inFIG. 10D, the average value of the output of the sensor array 42Lmonitoring the existence of the main subject is found as thedistance-measuring value.

[0110] Next, on the basis of the main subject distance obtained in stepS54, the ISO sensitivity of photographing mediums (including the imagingelement and film), and information on the zoom position obtained in stepS51, the guide number of the strobe unit is calculated. Then, it isdetermined whether strobe light reaches the main subject (step S58).

[0111] If it has been determined that strobe light reaches the mainsubject (YES), the average photometric value of the entire screen by theimaging element 20 is compared with the photometric value by the sensorarray 42 of the area where the main subject can possibly exist, therebydetermining whether the subject is against light (step S59). If theaverage photometric value of the entire screen is larger than thephotometric value of the main subject (YES), it is determined that thephotographic scene is against light. Then, exposure accompanied by theemission of strobe light is made (step S60), which completes thesequence.

[0112] If it has been determined in step S58 that the strobe light doesnot reach the main subject (NO), or if it has been determined in stepS59 that the photometric value of the main subject is larger than theaverage photometric value of the entire screen (NO), normal exposure ismade on the basis of the photometric value of the main subject (stepS61), which completes the sequence.

[0113] Consequently, with the second embodiment, a space correspondingto one light-receiving lens and the cost of one sensor array (externallight AF sensor) can be saved. The light-receiving lens and thephotographic lens can be provided with a wider space between them, withthe result that the base length B becomes longer and therefore higheraccuracy can be realized. In photometry by the AF sensor, one sensor 61can represent ten pixels of data of the imaging elements 62 a to 62 j,which enables the average value to be calculated easily at a high speed.Since consideration is given to whether strobe light reaches the mainsubject properly, it is possible to prevent the battery from beingconsumed due to a useless emission of strobe light.

[0114] Next, a third embodiment of the present invention will beexplained.

[0115]FIG. 13A shows an outward appearance of the camera viewed from thefront. FIG. 13B shows an internal configuration with the exterior of thecamera removed.

[0116] In the first and second modifications, the photometric sensors,distance-measuring sensors, and infrared photometric sensors have beenused. When they are mounted on the camera, various limits are set totheir locations, because the camera is required to be more compact andlighter. That is, the individual parts have to be mounted collectivelyso as not to allow a useless space, while assuring the performance ofthe camera.

[0117] The camera 71 is in the photographing standby state, with thefront cover 71 opened and the lens barrel 76 of the photographic lensprotruded. Above the lens barrel 76, the finder 72 and thedistance-measuring sensor 3 are provided side by side. At the top rightof the front, the strobe-emitting section 26 is provided. Thephotometric sensor 1 is provided below the finder 72 and in the vicinityof the lens barrel 76 and distance-measuring sensor 3.

[0118] On both sides between which the lens barrel 76 is sandwiched, aPatrone compartment 73 for loading a detachable film cartridge (notshown) and a spool compartment 74 provided with a spool (not shown) forwinding the film. On the underside of the camera body, there is provideda winder 75 that is coupled with the film cartridge and spool and feedsthe film. The film feeding includes winding and rewinding the film.

[0119] Below the finder 72 and in the place enclosed by the lens barrel76 and Patrone compartment 73, the remote control sensor, or theinfrared photometric sensor 52, is provided.

[0120] The photometric sensor 1 and infrared photometric sensor 52 areprovided in the space left after the primary component parts, includingthe lens barrel 76, Patrone compartment 73, and winder 75, areincorporated, which eliminates a useless space and therefore contributesto the miniaturization of the camera. The present invention is notlimited to the arrangement of the photometric sensors anddistance-measuring sensors. They have only to be provided in thevicinity of the finder. This arrangement helps reduce the parallax withrespect to the finder during photometry and distance measurement.

[0121] The less the parallax of each of the photometric sensor 1,distance-measuring sensor 3, and infrared photometric sensor 52 withrespect to the finder is, the more accurately the distance measurementand photometry of the subject desired by the user are performed.Although it is desirable that the photometric sensor 1,distance-measuring sensor 3, and infrared photometric sensor 52 shouldbe provided as close to the finder as possible, it is difficult toprovide a plurality of component elements in a specific place of thecamera from the viewpoint of the miniaturization of the camera. Sincethe infrared photometric sensor 52 has only to detect the infrared lightluminance of the whole subject field, there is no problem even when theparallax of the infrared photometric sensor 52 with respect to thefinder is greater than that of the photometric sensor 1 ordistance-measuring sensor 3. Therefore, in the third embodiment, theinfrared photometric sensor 42 is provided farther away from the finderthan the photometric sensor 1 and distance-measuring sensor 3, therebyrealizing not only accurate photometry and distance measurement but alsothe miniaturization of the camera.

[0122] As described above, with the first to third embodiments, even ina photographic scene where a decision on backlighting was difficult tomake in the prior art, proper exposure is made with a simple operationby comparing the photometric value of the area where the main subjectexists with the photometric value of the entire photographic screen,making a decision on the backlighting state correctly to determinewhether to emit strobe light, and making a decision on artificial lightto determine whether to emit strobe light. Therefore, it is possible toprovide an camera enabling the user to enjoy photography.

[0123] With the exposure control system of the embodiments of thepresent invention, it is possible to provide a camera capable of makinga decision on backlighting by comparing the luminance of the area wherethe main subject exists in the photographic screen with the averageluminance of the photographic screen and photographing the main subjectwith proper exposure without being influenced by the composition of thephotographic scene. Furthermore, the camera, which is provided with theartificial light judgment section, compares visible light with infraredlight. When light illuminating the subject is artificial, for example,fluorescent lamp light, the camera can photograph the subject withproper exposure so as to prevent color seepage, such as the greening ofthe image.

[0124] Next, a fourth to a seventh embodiments of a camera with aexposure control function according to the present invention will beexplained.

[0125]FIG. 14 shows an example of the basic configuration of a camerawith a photometric function according to the fourth embodiment of thepresent invention. The basic configuration is assumed to be equivalentto the basic configuration of cameras related to not only the fourthembodiment but also the fifth to seventh embodiments explained later.

[0126] A camera 80 includes a photometric section 81.for measuringinformation on the luminance of the subject in the photographic sceneand a distance-measuring section 82 for measuring information on thesubject distance on the same photographic scene. The camera 80 furtherincludes a lens driving section 83 for driving a focusing-lens on thebasis of the obtained distance-measuring information, a shutter section84 for exposing the film, a film feeding section 85 for winding andrewinding the film, and a strobe unit 86 for emitting light andilluminating the subject when the subject is low in luminance or againstlight.

[0127] The camera 80 further includes a nonvolatile memory, such asEEPROM 87, for storing various setting values and adjusting values forthe camera 80 and a CPU 88 for controlling the operation sequence of thewhole camera 80 and doing calculations.

[0128] The camera 80 further includes a 2-stage release switch composedof a first release switch (hereinafter, abbreviated as “1RSW”) 89 and asecond release switch (hereinafter, abbreviated as “2RSW”) 90. 1RSW89 isused for the photographer to inform the camera of the measuring ofinformation on the subject necessary for photography, such as distancemeasurements or photometry and the execution of calculations. 2RSW90 isused to inform the camera of the execution of photography on the basisof the measured and calculated subject information, after 1RSW89 hasbeen turned on.

[0129] The CPU 88 performs control of all of the camera according to arelease sequence program (often called a camera sequence program)serving as a virtual control program. In the control program, thefollowing sections are constructed in software: for example, they are afirst select section 91 for selecting the distance-measuring area whosedistance-measuring data indicates the closest distance from a pluralityof distance-measuring areas on the photographic screen, a second selectsection 92 for selecting the photometric area corresponding to thedistance-measuring area whose distance-measuring data indicates theclosest distance selected by the first select section and thephotometric area whose photometric data indicates the lowest luminancefrom its adjacent photometric areas, and a backlight judgment section 93for making a decision on backlighting on the basis of the differencebetween the photometric data about the photometric area with the lowestluminance selected by the second select section and the averagephotometric data on the photographic screen.

[0130] The distance-measuring section 81 and photometric section 82mounted on the camera 80 are configured as shown in FIGS. 15 and 16.

[0131]FIG. 15 schematically shows an example of the configuration of thephotometric section 81 related to the fourth to sixth embodiments. Thephotometric section 81 includes a photometric lens 101 for gatheringlight components at the photographic screen for photometricmeasurements, a multidivisional photometric sensor 102 for dividing thegathered light components into a plurality of regions and receivingthem, a photometric integration control section 103 for controlling theintegrating operation of the multidivisional photometric sensor 102, andan A/D conversion section 104 for converting the integration output ofthe multidivisional photometric sensor 102 from the analog signal into adigital signal, with the A/D conversion section 104 connected to themultidivisional photometric sensor 102. With this configuration, thedigital signal produced by a known photometric method to calculate thebrightness of the subject is supplied to the CPU 88.

[0132]FIG. 16 schematically shows the configuration of thedistance-measuring section 82 related to the fourth to sixthembodiments. The distance-measuring section 82 includes a pair oflight-receiving lenses 105 a, 105 b for forming the image of the subjectfor distance measurement, a pair of line sensors 106 a, 106 b forphotoelectrically converting the subject image formed by thelight-receiving lenses 105 a, 105 b according to their light intensityto produce an electric signal (subject image signal), adistance-measuring (AF) integration control section 107 for controllingthe integrating operation of the line sensors 106 a, 106 b, and an A/Dconversion section 108 for reading the subject image signal from theline sensors 106 a, 106 b and converting the analog signal into adigital signal. With this configuration, the digital signal which isproduced by a known distance-measuring method and used for calculatingthe distance to the subject is supplied to the CPU 88.

[0133] To help understand the characteristics of the fourth embodiment,the subject image in distance measurement and photometry and the areawhere the image can be detected will be explained.

[0134]FIG. 17 schematically shows the relationship between thephotometric area and the distance-measuring area in the fourthembodiment. In the areas for photometry and distance measurement, animage of a person 109, the main subject to be photographed, is emittedas shown in the figure. The areas for photometry and distancemeasurement are divided in a matrix on the finder screen (or imageforming screen), which forms the following types of areas.

[0135] In the fourth embodiment, the photometric section 81 measures theluminous intensity in each of the photometric areas divided into a largenumber of rectangles as shown by solid lines in FIG. 17. Thedistance-measuring section 82 measures the distance to each of therectangular distance-measuring areas arranged in the middle in thelongitudinal direction as shown by broken lines.

[0136] From the distance-measuring areas, the one whose measureddistance is the closest is selected. The photometric area correspondingto the selected distance-measuring area is selected. Thereafter, fromthe selected photometric area and the adjacent photometric areas on bothsides, the one whose photometric result is the lowest luminance isselected.

[0137] For example, when the distance-measuring area 110 presentsdistance-measuring data about the closest distance, an adjacentphotometric area 111 and an adjacent photometric area 113 are present onboth sides of the photometric area 112 corresponding to thedistance-measuring area 110.

[0138] Here, an algorithm related to the processes up to a decision onbacklighting will be explained.

[0139] For example, when the distance-measuring data about thedistance-measuring area 110 in FIG. 17 indicates the closest distance,the photometric area 112 is selected. It is assumed that the photometricdata items about the photometric area 112 and its adjacent photometricareas 111, 113 are B_(VAE) 112, B_(VAE) 111, and B_(VAE) 113,respectively, and their relationship in luminance level meets theexpression B_(VAE) 113<B_(VAE) 112<B_(VAE) 111. In this case, thephotometric data B_(VAE) 113 about the photometric area 113 whosephotometric data indicates the lowest luminance is selected.

[0140] Next, the average photometric data B_(VAE)AVE of the individualphotometric areas is determined. When the difference between the averagephotometric data B_(VAE)AVE and the photometric data B_(VAE) 113selected as described above is larger than a backlight decision valueGBvTH as a threshold value, it is determined that the subject is againstlight.

[0141] Specifically, with backlight decision value GBvTH=2EV, if thefollowing expression is met:

B _(VAE) AVE−B _(VAE) 113>2   (1)

[0142] it is determined that the photographic scene is against light.

[0143] If it is determined that the photographic scene is against light,the photometric data B_(VAE) 113 about the photometric area 113 is setas photometric data used in exposure calculations. On the other hand, ifit is determined that the photographic scene is not against light, theaverage photometric data B_(VAE)AVE about the photographic screen is setas photometric data used in exposure calculations.

[0144] The reason why the photometric data about the lowest luminance isselected from the photometric area corresponding to the closestdistance-measuring area and its adjacent photometric areas is that, whenthe closest distance-measuring area 110 includes both of the image of aperson 109, the main subject, and the background in the visual field asshown in FIG. 17, the photometric data B_(VAE) 112 about the photometricarea 112 corresponding to the distance-measuring area 110 has theaverage of the luminance of the image of a person 109 against light withthe high luminance background, with the result that it can possibly bedetermined that the photographic scene is not against light, even if thescene is actually against light.

[0145] As a modification of the fourth embodiment, the largestphotometric data in a plurality of photometric areas on the photographicscreen may be used in place of the average photometric data B_(VAE)AVEon the photographic screen, when a decision on backlighting is made.This prevents the photographic scene from being determined erroneouslyto be not against light in a case where the low luminance part occupiesa large proportion of the background of the main subject and the mainsubject itself is against light. Thus, it is possible to prevent theexposure of the main subject from being improper due to the misjudgment.

[0146] Furthermore, when a decision on backlighting is made, exposurecontrol may be performed with the emission of light from the strobeunit, instead of exposure control based on the lowest photometric data.In this exposure control, the main subject is exposed properly withstrobe light and the background is exposed properly for the exposuretime.

[0147] While the line sensors have been used in the distance-measuringsection 82, an area sensor may be used to make two-dimensional distancemeasurements. Use of the area sensor enables a decision on backlightingto be made in a much wider area on the photographic screen.

[0148] Next, the operation and control of the camera related to thefourth embodiment will be explained in detail. FIG. 19 shows a flowchartfor the release sequence of the camera provided with the photometricunit related to the fourth embodiment of the present invention. Thisflowchart serves as the main routine common to the fifth to seventhembodiments explained later.

[0149] First, when the power switch (not shown) of the camera is turnedon, previously stored data, including various setting values andadjusting values, are read from the EEPROM 87 and expanded into a RAM(not shown) in the CPU 88. Then, initial setting is done (step S71).

[0150] Next, it is determined whether the power switch is in the OFFstate (step S72). If the power switch is in the ON state (NO), it isdetermined whether 1RSW 89 is turned on (step S73). On the other hand,if the power switch is in the OFF state (YES), the sequence iscompleted.

[0151] If it has been determined in step S73 that 1RSW89 is in the ONstate (YES), a specific photometry is performed and photometric dataabout each of the photometric areas on the photographic screen iscalculated (step S74). On the other hand, if 1RSW89 is in the OFF state(NO), control returns to step S72 and is standing by.

[0152] Next, a specific distance measurement is made anddistance-measuring data about each of the distance-measuring areas onthe photographic screen is calculated (step S75). Thereafter, on thebasis of the result of the photometry obtained in step S74 and theresult of the distance measurement in step S75, a decision onbacklighting explained later is made (step S76).

[0153] On the basis of the exposure computing data set in the decisionon backlighting in step S76, exposure calculations are done, therebydetermining exposure control data (step S77). On the basis of thecalculated subject distance data, the amount of protrusion of thefocusing lens (not shown) is calculated (step S78).

[0154] After the calculations are completed, it is determined whether1RSW89 is in the ON state (step S79). If 1RSW89 is in the ON state(YES), it is determined whether 2RSW90 is in the ON state (step S80). Onthe other hand, if 1RSW89 is not in the ON state (NO), control returnsto step S72.

[0155] If it has been determined in step S80 that 2RSW90 is in the ONstate (YES), the lens driving section 83 protrudes the focusing lensaccording to the amount of lens protrusion determined in step S78 (stepS81). On the other hand, if 2RSW90 is not in the ON state (NO), controlreturns to step S79.

[0156] Next, after the protrusion of the lens is completed, the shuttersection 84 makes exposure according to the exposure control dataobtained in step S77 (step S82). Thereafter, the film feeding section 85rolls up one frame of the film. Then, control returns to step S72 again.

[0157] Referring to a flowchart shown in FIG. 20, a characteristicsubroutine “backlight decision” in the fourth embodiment will beexplained.

[0158] First, the closest distance-measuring data is found from thedistance-measuring data about each of the distance-measuring areas onthe photographic screen measured in step S75 of FIG. 19. Then, thedistance-measuring area corresponding to the closest distance-measuringdata is selected (step S91). Next, the photometric area corresponding tothe selected distance-measuring area is selected (step S92). From theselected photometric area and its adjacent photometric areas, the lowestluminance photometric data is selected (step S93).

[0159] Next, from the photometric data about the individual photometricareas in step S74 of FIG. 19, the average photometric data (B_(VAE)AVE)on the photographic screen is determined (step S94). Furthermore, thedifference between the lowest luminance photometric data selected instep S93 and the average photometric data found in step S94 iscalculated (step S95).

[0160] Then, the difference between the lowest luminance photometricdata and the average photometric data calculated in step S95 is comparedwith a specific backlight decision value (threshold value: GBVTH=2EV)using expression (1) (step S96). In the comparison, if the difference inthe photometric data (B_(VAE)AVE−B_(VAE) 113) is larger than thebacklight decision value (2: in the fourth embodiment), it is determinedthat the photographic scene is against light (YES) and the lowestluminance photometric data selected in step S93 is set in the exposurecomputing data (step S97). Thereafter, control returns to step S77 ofFIG. 19. On the other hand, if the difference in the photometric data isnot larger than the backlight decision value (NO), it is determined thatthe photographic scene is not against light and the average photometricdata B_(VAE)AVE on the photographic screen found in step S94 is setdirectly in the exposure computing data (step S98). Thereafter, controlreturns to step S77 of FIG. 19.

[0161] Next the fifth embodiment of the present invention will beexplained.

[0162] The fifth embodiment is a photometric unit whose configuration isequivalent to that of the fourth embodiment, and so an explanation ofits configuration will be omitted.

[0163] To help understand the characteristics of the fifth embodiment,the image of a subject in photometry and distance measurement and thearea where the image can be detected will be explained.

[0164]FIG. 18 shows the relationship between the photometric area andthe distance-measuring area in the fifth embodiment. In the areas forphotometry and distance measurement, an image of a person 114, the mainsubject to be photographed, is emitted as shown in the figure. The areasfor photometry and distance measurement are divided in a matrix on thefinder screen (or image forming screen), which forms the following typesof areas.

[0165] For distance-measuring data about each distance-measuring area,for example, there are a distance-measuring area 115 whosedistance-measuring data indicates the closest distance and adjacentdistance-measuring areas 116 and 117 on both sides of thedistance-measuring area 115.

[0166] Here, an algorithm related to the processes up to a backlightdecision will be explained.

[0167] For example, of a plurality of rectangular areas arranged in themiddle in the longitudinal direction shown by broken lines in FIG. 18,the distance-measuring data about the distance-measuring area 115indicates the closest distance, photometric data B_(VAF) 115, B_(VAF)116, B_(VAF) 117 are determined in the photometric area 115 and itsadjacent photometric areas 116, 117. If their level relationship inluminance level meets the expression B_(VAF) 117<B_(VAF) 115<B_(VAF)116, photometric data B_(VAF) 117 about the distance-measuring area 117whose photometric data has the lowest luminance is selected.

[0168] Next, the average photometric data B_(VAE)AVE of the individualphotometric areas is determined. When the difference between the averagephotometric data B_(VAE)AVE and the photometric data B_(VAF) 117selected as described above is larger than a backlight decision valueGBvTH, it is determined that the photographic scene is against light.

[0169] Specifically, with the backlight decision value GBvTH=2EV, if thefollowing expression is met:

B _(VAE) AVE−B _(VAF) 117>2   (2)

[0170] it is determined that the photographic scene is against light.

[0171] If it has been determined that the photographic scene is againstlight, the strobe unit 86 is caused to emit light during exposure. If ithas been determined that the photographic scene is not against light,the average photometric data B_(VAE)AVE on the photographic screen isset as photometric data used in exposure calculations.

[0172] The operation and control in the fifth embodiment will beexplained.

[0173]FIG. 21 is a flowchart for the sequence of a characteristicsubroutine “backlight decision” in the fifth embodiment. FIG. 21 is abacklight decision subroutine in step S76 of FIG. 19.

[0174] First, from the distance-measuring data about thedistance-measuring areas on the photographic screen measured in step S75of FIG. 19, the closest distance-measuring data is found. Thedistance-measuring area corresponding to the closet distance-measuringdata is selected (step S101). The photometric data about the selecteddistance-measuring area and the photometric data about its adjacentdistance-measuring areas are found (step S102).

[0175] Next, from the photometric data found in step S102, the lowestluminance photometric data is selected (S103). From the photometric dataabout the photometric areas in step S74 of FIG. 19, the averagephotometric data (B_(VAE)AVE) on the photographic screen is calculated(step S104).

[0176] Next, the difference between the lowest luminance photometricdata selected in step S103 and the average photometric data found instep S104 is calculated (step S105). The difference between the lowestluminance photometric data and the average photometric data calculatedin step S105 is compared with the backlight decision value (GBvTH=2EV)using the expression (2), thereby making a decision on which is largeror smaller (step S106).

[0177] If it has been determined that the difference in the photometricdata is larger than the backlight decision value (2: in the fifthembodiment) (YES), it is determined that the photographic scene isagainst light. To deal with the backlighting state, strobe lightemission request setting is done by, for example, setting a strobe lightemission request flag at the strobe unit 86 (step S107). Thereafter,control returns to step S77 of FIG. 19. On the other hand, if thedifference in the photometric data is not larger than the backlightdecision value (NO), it is determined that the photographic scene is notagainst light and the average photometric data on the photographicscreen obtained in step S104 is set directly in the exposure computingdata (step S108). Thereafter, control returns to step S77 of FIG. 19.

[0178] As described above, with the fifth embodiment, the luminance ofthe main subject in making a decision on backlighting is found using thedistance-measuring section 82, which not only produces a similar effectto that of the fourth embodiment but also can make a similar backlightdecision without using the multidivisional photometric element 102 (FIG.15) in the photometric section 81.

[0179] Next, the sixth embodiment of the present invention will beexplained.

[0180] In the fourth and fifth embodiments, when it has been determinedthat the photographic scene is against light, the strobe unit 86 iscaused to emit light during exposure. In actual photographing, however,there may be a case where a sufficient effect cannot be obtained evenwhen supplementary light is supplied by the strobe unit 86, because ofvarious conditions, including the photographic lens with a large FNo.,the photographic scene with a long subject distance, and a low filmsensitivity. Since the configuration of the sixth embodiment isequivalent to that of the fourth embodiment, its detailed explanationwill be omitted.

[0181] In the sixth embodiment, when it is determined that thephotographic scene is against light and supplementary light from thestrobe unit 86 cannot produce an acceptable effect, exposure control isperformed on the basis of the lowest luminance photometric data selectedfrom the photometric area corresponding to the closestdistance-measuring area and its adjacent photometric areas.

[0182] A decision on backlighting in the sixth embodiment will beexplained by reference to a flowchart show in FIG. 22. FIG. 22 shows asubroutine for a decision on backlighting in step S76 of FIG. 19.

[0183] First, from the distance-measuring data about thedistance-measuring areas on the photographic screen measured in step S75of FIG. 19, the closest distance-measuring data is found. Then, thedistance-measuring area indicating the value of the closestdistance-measuring data is selected (step S111). The photometric areacorresponding to the selected distance-measuring area is selected (stepS112).

[0184] From the photometric area selected in step S112 and its adjacentphotometric areas, the lowest luminance photometric data is selected(step S113). From the photometric data about the individual photometricareas in step S74 of FIG. 19, the average photometric data on thephotographic screen is found (step S114). Furthermore, the differencebetween the lowest luminance photometric data selected in step S113 andthe average photometric data found in step S114 is calculated (stepS115).

[0185] Next, the difference between the lowest luminance photometricdata and the average photometric data calculated in step S115 iscompared with the backlight decision value (step S116). In thecomparison, if the difference in the photometric data is larger than thebacklight decision value (YES), it is determined that the photographicscene is against light. Furthermore, the effect of emittingsupplementary light from the strobe unit 86 in the backlighting state isestimated (step S117). That is, it is determined whether the closestdistance-measuring data is within strobe light reaching distance isdetermined, taking into account the FNo. of the photographic lens andthe film sensitivity. On the other hand, if the comparison in step S116has shown that the difference in the photometric data is not larger thanthe backlight decision value (NO), it is determined that thephotographic scene is not against light and the average photometric dataon the photographic scene found in step S114 is set in the exposurecomputing data (step S120). Thereafter, control returns to step S77 ofFIG. 19.

[0186] In step S117, if the closest distance-measuring data is withinstrobe light reaching distance (YES), it is determined thatsupplementary light will produce effects. Then, strobe light emissionrequest setting is done by setting a light emission request flag in thestrobe unit 86 (step S118). Thereafter, control returns to step S77 ofFIG. 19. On the other hand, if the closest distance-measuring data isnot within strobe light reaching distance (NO), the lowest luminancephotometric data selected in step S113 is set in the exposure computingdata (step S119). Thereafter, control returns to step S77 of FIG. 19.

[0187] As described above, with the sixth embodiment, since it isdetermined whether the value of the obtained closest distance-measuringdata is within strobe light reaching, taking into account the FNo. ofthe photographic lens and the film sensitivity, the effect of strobelight can be estimated. Therefore, even when the emission of light fromthe strobe unit 86 doesn't seem to have any effect in the backlightingscene, the main subject can be photographed with as proper exposure aspossible by setting the lowest luminance photometric data in theexposure computing data.

[0188] Next, the seventh embodiment of the present invention will beexplained.

[0189]FIG. 23 schematically shows the configuration of a photometricsection and a distance-measuring section in the seventh embodiment. Theseventh embodiment is characterized by using a pair of area sensors 122a, 122 b as shown in FIG. 23 in place of the distance-measuring section82. Photometry is performed using one of the area sensors 122 a, 122 b.

[0190] A photometric distance-measuring section 125 in the seventhembodiment measures subject luminance data and subject image data. Thephotometric distance-measuring section 125, which has the functions ofthe photometric section 81 and distance-measuring 82, is an integralphotometric distance-measuring unit sharing a sensor function. Thephotometric distance-measuring section 125 is composed of a set oflight-receiving lenses 121 a, 121 b, area sensors 122 a, 122 b, anintegration control section 123, and an A/D conversion section 124.

[0191] Of these, the light-receiving lenses 121 a, 121 b form a subjectimage on the light-receiving surface of the area sensors 122 a, 122 b.The area sensors 122 a, 122 b photoelectrically convert the subjectimage formed on the light-receiving surface and produce an electricsignal (photometric data or subject image signal) according to the lightintensity. The integration control section 123 performs control relatedto the integrating operation of the area sensors 122 a, 122 b. The A/Dconversion section 124 reads the photometric data or subject imagesignal produced by the area sensors 122 a, 122 b and converts the dataor analog signal into a digital signal.

[0192] That is, in place of the line sensors (106 a, 106 b) used in thedistance-measuring section 82, the area sensors 122 a, 122 b are usedfor distance measurements. At least one of the area sensors is used forphotometry.

[0193] With this configuration, distance measurement and photometry areperformed as described above. The processing sequence of distancemeasurement and photometry conform to that in the aforementionedembodiments and its detailed explanation will be omitted. In photometry,two-dimensional photometric processing can be done using an area sensor.Therefore, for example, the photometric areas for the main subject maybe set arbitrarily in a two-dimensional space (or two-dimensionally).The photometric points may be designed to be compatible withmulti-points, if necessary.

[0194] As described above, with the seventh embodiment, the photometricsection 81 becomes unnecessary and the photometric section anddistance-measuring section share the light-receiving element (areasensor), which makes it possible to provide an integral photometricdistance-measuring unit. Sharing the light-receiving element eliminatesparallax in the photometric visual field and distance-measuring visualfield. Therefore, the seventh embodiment has a spatial merit and enablesa higher-accuracy backlight decision to be made than a conventionalequivalent.

[0195] Explanation has been given using a camera capable of photometryand distance measurement as an example. The subject matter of thepresent invention may be applied similarly to devices other thancameras. The invention, of course, may be applied similarly to a singledevice unit, such as a photometric distance-measuring unit.

[0196] Next, an eighth embodiment of the present invention will beexplained.

[0197]FIG. 24 is a block diagram of a camera according to the eighthembodiment. First, the image of a subject (person) 143 is formed by aphotographic lens 135. The image-enters an imaging section 137 theimaging section 137 separates the image of the subject 143 into threekinds of color components (i.e., RGB components) and integrates them.The amounts of integration corresponding to the respective colorcomponents are outputted as subject image signals to an analog/digital(A/D) conversion section 137 a. The A/D conversion section 137 aconverts the inputted integration output into digital quantity andoutputs the digital signal to an image processing section 140 a.

[0198] The digital integration output (hereinafter, referred to as imagedata) inputted to the image processing section 140 a is subjected totone correction at a tone correcting section 138. The tone correction isknown as a gamma (γ) conversion process. In the tone correction, the γvalue in the tone curve of the inputted data is corrected, therebymaking the brightness of the image proper. The tone correcting section138 emphasizes the dark part or the bright part, which makes natural thedistribution of brightness of the screen visible to our eyes inreproducing the image.

[0199] After the tone is corrected by the tone correcting section 138,the tone correcting section 138 supplies its output to an RGB signal/YCsignal (RGB/YC) converting section 139. The RGB/YC converting section139 converts the image data inputted in the form of a RGB componentsignal into a luminance (Y) signal and a color coordinate (CR, CB)signal. Of the signals converted into the YC components, the luminancesignal is outputted to a contour emphasizing section 140 and the colorcoordinate signal is outputted to an image compressing section 141.

[0200] The contour emphasizing section 140 carries out a contouremphasizing process of emphasizing the high contrast part of theinputted image (generally knows as a sharpness process). The contouremphasizing process will be explained later.

[0201] The image thus processed is inputted from the image processingsection 140 a to the image compressing section 141. The imagecompressing section 141 compresses the inputted image using JPEG or thelike and then records the compressed image into a recording section 142.

[0202] As described above, the photographed image is recorded into therecording section 142 digitally. Such a series of image processes arecarried out by a computing section (CPU) 131 composed of a one-chipmicrocomputer or the like. The CPU 131 also performs photographingcontrol of the camera. The CPU 131 includes the functions of thebacklighting state judgment section and image processing section.

[0203] According to the signal from the CPU 131, the shutter section 137b controls the charge accumulation time of the imaging section 137composed of CCD or the like. Before photographing, the CPU 131 focusesthe photographic lens 135 via a photographic lens driving (LD) section135 a. Focusing may be done on the basis of the subject distance dataobtained from the output of an A/D converting section 134.Alternatively, focusing may be done on the basis of the peak value ofthe contrast signal obtained from the image processing section 140 a.The image processing section 140 a produces the contrast signal bydisplacing the photographic lens 135 little by little.

[0204] The subject distance is calculated as follows. First, the imagesof the subject 143 obtained via the two light-receiving lenses 132 a,132 b provided the base length (parallax) B apart are formed on thesensor arrays 133 a, 133 b. At this time, from the image positiondifference x of the image of the subject 143 based on the parallax ofthe light-receiving lenses 132 a, 132 b, the CPU 131 calculates thesubject distance according to the principle of trigonometrical distancemeasurements.

[0205] Use of the image (hereinafter, referred to as the image signal)of the subject 143 formed on the sensor arrays 133 a, 133 b or theimaging section 137 makes it possible to check if the subject 143 isdark or against light.

[0206] Specifically, the subject 143 often exists in the middle of thescreen in terms of probability. In the case of FIG. 26A, since the imageat left is brighter than in the middle, it can be determined that thesubject is against light.

[0207] Furthermore, if the image data is low in luminance even after aspecific time of integration, or after the charge is accumulated, it canbe determined that the subject has a low luminance. The higher theintensity of the incident light is, the larger photoelectric current thesensor arrays 133 a, 133 b and the imaging section 137 generate.Therefore, when the photoelectric current is integrated to a specificcapacity, the brighter the part, the larger the integration value, orthe darker the part, the smaller the integration value.

[0208] In FIG. 24, the distance-measuring unit is composed of thelight-receiving lenses 132 a, 132 b, sensor arrays 133 a, 133 b, and A/Dconverting section 134. The distance-measuring unit sets the subjectexisting at the point indicating the closest distance as the mainsubject and determines whether the subject is bright or dark on thebasis of the brightness of the point. That is, the distance-measuringunit determines whether the subject is against light, on the basis ofthe comparison with the integration values of the surroundings.

[0209]FIG. 25 shows the region monitored by both of the sensor arrays asregion 133 c and the region monitored by the imaging section 137 asregion 137 c. When the subject 143 is dark or against light, a strobelight emission circuit 136 a performs light emission control of a strobelight emission section 136, thereby supplementing the exposure of thesubject 143.

[0210] Next, FIG. 26A shows an example of the photographic scenesupposed in the eighth embodiment. When the person 143, the mainsubject, is against light, the luminance difference between thebackground and the person becomes larger. At this time, in FIG. 26A, forexample, when the brightness in the x-direction with respect to theposition of a specific coordinate y0 in the vertical direction of thephotographic screen is monitored, the characteristic as shown in FIG.26B is obtained. In the FIG. 26B, the position corresponding to thebackground is bright and the position corresponding to the person 143 isdark. At this time, since the photographic scene of FIG. 26A is againstlight, the left half of the person 143 influenced by outdoor light isbright and the right half of the person 143 inside the house is dark. Insuch a case, when exposure is made so that the subject may lie withinthe permitted luminance range, there is a possibility that the contourof either the background or the person will disappear. In such a state,when the above-described contour emphasizing process or y conversionprocess is carried out, an erroneous contour appears, noise occurs inthe dark part, or the bright part disappear in white, which results inan unnatural image.

[0211] This will be explained in more detail by reference to a histogramshown in FIG. 27A. In FIG. 27A, the abscissa axis indicates brightness(luminance) Bv and the ordinate axis indicates in frequency how manypixels of the brightness indicated by the abscissa axis there are. Sincein a backlighting scene, the difference in brightness between the brightpart and the dark part is large, the ratio of the number of pixelsoutputting bright data to the total number of pixels and the ratio ofthe number of pixels outputting dark data to the total number of pixelsare high, whereas the number of pixels outputting intermediate data issmall. As a result, a larger part of the image cannot be recognizedvisually. When the γ conversion process is performed on FIG. 27A so asto decrease the γ value, the result is as shown in FIG. 27B.

[0212] The γ conversion process at that time will be explained byreference to FIG. 29.

[0213]FIG. 29 shows how the brightness of the input and output imagesvaries according to the γ value in the y conversion process.Specifically, when the γ value becomes small (in the figure, γ=0.56),the dark part of the image is emphasized, making it easier to see achange in the dark part of the image. The bright part of the image iscorrected so that a change in the bright part may be weakened. On theother hand, when the γ value becomes large (in the figure, γ=1.8), thedark part of the image gets darker, being painted over with black, and achange in the bright part of the image is emphasized.

[0214] Therefore, when FIG. 27A is subjected to the y conversion processto decrease the γ value, the dark part in FIG. 27A is emphasized, withthe result that the emphasized part lies in the visually recognizablerange. From the beginning, the dark part has a small signal quantity andtherefore the noise-to-signal ratio is relatively high. When the darkpart is emphasized in such a case, the noise component of the signal isemphasized, too. This impairs the discontinuity of gradation, renderingthe image undergone γ-conversion even worse.

[0215] In the eighth embodiment, to overcome this problem, the strobelight emission section 136 is caused to emit light in the photographicscene as shown in FIG. 26A, thereby obtaining an image as shown in FIG.26C, that is, such an image as brings both the background and the mainsubject into the visually recognizable range, not an image against lightas shown in FIG. 28.

[0216] That is, when a luminance distribution with a large luminancedifference as shown in FIG. 26B or a histogram as shown in FIG. 27A hasbeen obtained from the sensor arrays 133 a, 133 b or the imaging section137, strobe light is emitted and the light quantity at the main subjectis supplemented as shown in FIG. 26D, thereby raising the luminancedistribution, which brings the background and the image of the personinto a specific latitude. In the histogram, the intermediate brightnessis increased with the supplementary light from the strobe unit as shownin FIG. 27C, which makes it possible to record the image with exposuresacrificing the dark part. In this case, it is not necessary toemphasize a specific brightness in the γ conversion process. Therefore,the contour emphasizing process is a normal one.

[0217] The contour emphasizing process will be explained in more detailby reference to FIGS. 30A and 30B. FIG. 30A shows the processes carriedout in the contour emphasizing section 140 of FIG. 24 from a functionalviewpoint.

[0218] When the luminance signal data (input Y in FIG. 30A) 152converted at the RGB/YC converting section 139 is inputted to thecontour emphasizing section 140, a contour component extracting circuit140A in the contour emphasizing section does Laplacian calculation ofthe inputted luminance signal data 152 using a sharpening filter matrix151 (FIG. 30B). As a result, the image data whose central part isemphasized, or the contour signal data 153, is created. The contoursignal data 153 contained the noise component of the luminance signaldata 152, which has been emphasized. Thus, the image will appearunnatural if the contour emphasis is performed by using the contoursignal data 153 acquired for all pixels. Therefore, a limiting circuit140B prevents the result of calculations lower than a specific contrast,or less than ΔY in the figure from being inputted to an adder circuit140C.

[0219] On-the other hand, the luminance signal data 152 is also inputtedto the adder circuit 140C, with the result that the combination of theluminance signal date 152 and the contour signal data 153 becomes thefinal output Y′ of the contour emphasizing section 140.

[0220] By changing the invariables in the sharpening filter matrix, thedegree of contour emphasis can be changed. In addition, the degree ofcontour emphasis is also changed by changing ΔY in the limiting circuit140B. In this case, making ΔY larger causes contour emphasis to bedecreased, whereas making ΔY smaller causes contour emphasis to beincreased.

[0221] Since there is a limit to the guide number showing therelationship between the strobe light reaching distance and the stop ofthe camera, when the subject distance is too far, the main subjectcannot be brought into a sufficient brightness, no matter how strong thestrobe light is. As a result, an image as shown in FIG. 26E appears.

[0222] As described above, when the strobe light does not reach the mainsubject, exposure is made so as to bring only the bright part intolatitude 1 of FIG. 26F, with the result that the face of the person 143becomes pitch-dark at the cost of the background photographed properlyas shown in FIG. 26E. Thus, in such a scene, exposure is made on theoverexposure side, that is, in latitude 2 of FIG. 26F, which permits theface of the person 143 to be photographed properly. Then, in the γconversion process, the γ value is made larger to emphasize the brightpart, or a change in the luminance of the background, so that the imageof the background may not collapse. At this time, since the largeluminance difference still remains, contour emphasis would make theimage unnatural. Therefore, contour emphasis is caused to weaken.

[0223] Referring to a flowchart shown in FIG. 31, the sequence ofphotographing control performed by the CPU 131 based on theaforementioned idea will be explained.

[0224] First, when photographing control is started, distancemeasurement to calculate the subject distance is made to determine aphotographic scene in photographing (step S131). Next, on the basis ofthe calculated subject distance, the LD section 135 a is controlled tofocus the photographic lens 135 (step S132). In addition, photometry isperformed to detect the brightness at the photographic screen and thedistribution of brightness (step S133). Next, on the basis of theobtained data, it is determined whether the photographic scene isagainst light (step S134).

[0225] Specifically, if the image data about the main subject 143 formedon the sensor arrays 133 a, 133 b or imaging section 137 is much smallerthan the image data about the background, it is determined that thephotographic scene is against light. The method of detecting the mainsubject may be a method of detecting the distance distribution on thescreen with the distance-measuring unit as described above anddetermining the thing indicating the closest distance to be the mainsubject. Alternatively, a known method may be used. This method is todetect the contour of the subject from the data generated by the imagingsection 137. If the shape represents a man, the subject is determined tobe the main subject.

[0226] If it has been determined in step S134 that the photographicscene is against light, the light emission flag of the strobe unit isset high (step S135). Then, from the subject distance obtained in stepS131, the strobe light emission quantity GNo is calculated by a knownflashmatic method (step S136). Next, when the strobe light emissionsection 136 has been caused to emit light, it is determined whetherstrobe light reaches the subject, that is, whether the subject distanceobtained in step S131 is closer than the strobe light reaching distance(step S137).

[0227] If it has been determined in step S137 that strobe light reachesthe subject (YES), it is determined from the background image datawhether the exposure of the background exceeds a specific value (stepS138).

[0228] In step S138, it is determined whether exposure is made so thatthe background can be visually recognized. That is, it is determinedwhether exposure is brought to such overexposure that the backgroundcannot be visually recognized. More specifically, the determination ismade on the basis of whether the amount of exposure of the backgroundexceeds the upper limit of the latitude of the imaging section 137.Therefore, if the latitude of the imaging section 137 is ±2EV, thespecific amount is +2EV. Then, it is determined whether exposure of thebackground exceeds +2EV. In step S138, if it has been determined thatexposure of the background exceeds the specific value (YES), setting isdone in the γ conversion process so that the γ value is increased (stepS139) and contour emphasis is weakened (step S140) and then controlproceeds to step S153. Making the γ value larger prevents the backgroundimage from disappearing in white as described earlier. Since thebackground light can be blurred with the contour of the main subject,correction to weaken contour emphasis is made at the same time. On theother hand, in step S138, if it has been determined that exposure of thebackground does not exceed the specific amount (NO), setting is done sothat correction is made with the normal γ value, that is, γ=1 (stepS141) and then control goes to step S153. In this case, it is notnecessary to change the setting of contour emphasis, because thebrightness of the background image is balanced with that of the mainsubject.

[0229] In step S137, if it has been determined that strobe light doesnot reach the main subject (NO), it is determined whether theunderexposure of the main subject is equal to or less than −2EV underthe irradiation of strobe light (step S142). In step S142, it isdetermined whether exposure is made so that the main subject can bevisually recognized. That is, it is determined whether exposure isbrought to such underexposure that the main subject cannot be visuallyrecognized. The threshold of the determination is not limited to −2EVand may be set so that it can be determined whether exposure is made soas to enable the main subject to be visually recognized. Morespecifically, the threshold can be determined on the basis of whetherthe amount of exposure of the main subject drops below the lower limitof the latitude of the imaging section 137. In the eighth embodiment,let the latitude of the imaging section 137 be ±2EV. Thus, in step S142,it is determined whether the underexposure of the main subject is equalto or less then −2EV. In step S142, if it has been determined that theunderexposure is not equal to or less than −2EV, setting is done so asto make an exposure correction of +1EV (step S143), because theillumination of the main subject by strobe light is regarded as makingalmost no contribution to exposure. As a result, the dark part is madebrighter.

[0230] This makes it possible to cause the amount of exposure of themain subject to lie within the latitude of the imaging section 137. Theamount of corrected exposure is not restricted to +1EV and may bedetermined so that, for example, the amount of exposure of the mainsubject may lie within the latitude of the imaging section 137. Whenexposure is corrected excessively, the high luminance part, such as thebackground, is overexposed. Therefore, the amount of corrected exposuremay be determined so that the amount of exposure of the main subject andthat of the background may lie within the latitude of the imagingsection 137 according to the difference in the amount of exposurebetween the main subject and the background. Thereafter, setting is doneso that the γ value may be increased (step S144) and contour emphasismay be decreased (step S145) and then control goes to step S153. On theother hand, in step S142, if it has been determined that the degree ofthe underexposure is equal to or less than −2EV, setting is done so thatthe γ value may be increased (step S146) and contour emphasis may bedecreased (step S147) and then control goes to step S153.

[0231] In step S134, if it has been determined that the photographicscene is not against light, it is determined from the photometric valuethat the strobe light emission section 136 is caused to emit light (stepS148). If it has been determined that the strobe light emission section136 is caused to emit light (YES), the light emission flag of the strobeunit is set high (step S149). Thereafter, setting is done so that the γvalue may be decreased (step S150) and contour emphasis may be decreased(step S151) and then control goes to step S153. At this time, the γvalue is made smaller and the dark part is made as bright as possible.In this case, however, since the hair of the person 143 often cannot bedistinguished from the dark background as shown in FIG. 32, correctionto weaken contour emphasis is made.

[0232] On the other hand, in step S148, if it has been determined thatthe strobe light emission section 136 is not caused to emit light (NO),setting is done so that a y correction may be made with a normal γ value(step S152) and then control proceeds to step S153.

[0233] After the above operation, it is determined whether the lightemission flag of the strobe unit is high (step S153). If it has beendetermined that the light emission flag of the strobe unit is high(YES), it is determined whether setting has been done to make anexposure correction (step S154). If it has been determined that settinghas been done to make an exposure correction (YES), strobe photographingwith an exposure correction is done (step S155) and then control goes tostep S158. In step S153, if it has been determined that the lightemission flag of the strobe unit is not high (NO), normal photographingwithout the light emission of the strobe light emission section 136 isdone (step S156). Thereafter, control goes to step S158. In step S154,if it has been determined that setting has not been done so that anexposure correction may be made (NO), strobe photographing without anexposure correction is done (step S157) and then control proceeds tostep S158.

[0234] After the image has been photographed by the above-describedoperations, the image processes, including the γ conversion process andcontour emphasizing process, are carried out according to theaforementioned settings (step S158) and the photographed image isrecorded into the recording section 142 (step S159). After thephotographed image is recorded into the recording section 142, thephotographing control sequence is completed.

[0235] As described above, with the eighth embodiment, light issupplemented by the strobe unit according to the state of thephotographic scene (such as backlighting) and a proper exposurecorrection and image processing are selected automatically, therebyperforming photographing control. Therefore, proper photographing can bedone even in a photographic scene against light which would be difficultto reproduce in the prior art. Furthermore, since the photographer neednot operate to make the correction, a camera excellent in snapshotcapabilities can be provided.

[0236] Next, a ninth embodiment of the present invention will beexplained by reference to FIG. 33.

[0237] In the ninth embodiment, instead of using a distance-measuringunit, or the sensor arrays 133 a, 133 b, and the like, the imagingsection provided on the digital camera or the like, or the imagingsection 137 of FIG. 24, is used to measure a distance. The CPU 131 inthe ninth embodiment includes the functions of an illumination statejudgment section and a control section. Since the remainingconfiguration and operation are the same as those in the eighthembodiment, explanation of them will be omitted.

[0238]FIG. 33 is a flowchart to help explain operation control beforephotographing is done with a camera according to the ninth embodiment.The operations subsequent to the flowchart are almost the same as thoseafter step S134 in FIG. 31.

[0239] First, the CPU 131 takes in an image with the imaging section 137(step S161). Then, the contrast of the taken-in image is detected (stepS162). Next, it is determined whether the detected contrast is the peakof the contrast (step S163). If it has been determined that it is notthe peak of the contrast (NO), the photographic lens 135 is drivenminutely (step S167) and then control returns to step S161. Theseoperations are repeated until the peak of the contrast has beendetected.

[0240] On the other hand, if it has been determined in step S163 thatthe peak of the contrast has been detected (YES), it is determined fromthe brightness of the image whether the emission of strobe light isnecessary (step S164). If it has been determined that the emission ofstrobe light is not necessary (NO), control exits the flowchart andproceeds to step S134 in FIG. 31. In subsequent processes, photographingis done without the light emission of the strobe light emission section136.

[0241] In step S164, it has been determined that the emission of strobelight is necessary (YES), a pre-emission of a small quantity of light iscarried out and the image at this time is taken in by the imagingsection 137 (step S165). Comparing the image with the image taken in atstep S161 enables the contribution rate of strobe light duringphotographing. From this, information as to whether strobe light reachesthe subject during photographing or whether the exposure state by theirradiation of strobe light is in underexposure is estimated and thenthe proper amount of emission of strobe light is calculated (step S166).After the amount of emission of strobe light is calculated, controlexits the flowchart and goes to step S134 in FIG. 31.

[0242] For example, in step S161, if the amount of integration as shownin FIG. 34A, or the image data, is obtained, and the image data as shownin FIG. 34B or FIG. 34C is obtained with the pre-emission of light instep S164, the difference (indicated by STUP in the figure) betweenFIGS. 34A and 34B or FIGS. 34A and 34C indicates the rate of thecontribution of strobe light.

[0243] After the pre-emission of light, when the image data in FIG. 34Bis obtained, the central part, or the main subject, is less bright thanthe background. Therefore, since the strobe light is regarded as makingno contribution, step S138 in FIG. 31 is branched to step S139. On theother hand, after the pre-emission of light, when the image data in FIG.34C is obtained, the brightness of the background and that of the mainsubject are almost at the same level, so that step S138 in FIG. 31 isbranched to step S141.

[0244] As explained above, with the ninth embodiment, suitablephotographing control is performed according to the photographic scenewith the imaging section of the digital camera without using a specialdistance-measuring unit. This makes it possible to photograph abacklighting scene which was difficult to reproduce in the prior art,without using a special distance-measuring unit.

[0245] Next, referring to FIGS. 35 to 38, a tenth embodiment of thepresent invention will be explained. The configuration of the tenthembodiment is achieved by applying an equivalent configuration to thatof the eighth or ninth embodiment.

[0246] In the tenth embodiment, when the photographic scene is againstlight and strobe light emission control is performed, control isperformed so that the background and a person, the main subject, mayhave a proper brightness. This will be explained by reference to FIGS.36A and 36B. FIG. 36A shows a change in the amount of integration of thebackground subject with respect to time after the emission of strobelight. At this time, the strobe light does not reach the backgroundsubject. Since the photographic scene is against light from thebeginning, the background subject is exposed at the proper level for theproper exposure time even under only steady light components, such asnatural light.

[0247]FIG. 36B shows a change in the amount of integration of the mainsubject with respect to time after the emission of strobe light. At thistime, the steady light components of the main subject are supplementedwith strobe light, which enables exposure to be made at the proper levelfor the proper exposure time.

[0248] There is a limit to the amount of emission of strobe light.Therefore, only with steady light, such as natural light, it is possiblethat the main subject has not yet been exposed at the proper level, evenwhen the background has been exposed at the proper level for the properexposure time as shown in FIGS. 37A and 37B. In FIG. 37B, the differencebetween the amount of integration of the main subject and that of thebackground subject (at the proper exposure level) is represented as theamount of underexposure in FIG. 37B. The amount of underexposure can beestimated on the basis of the result of photometry and the result ofdistance measurement before photographing and the limit of guide numberof the strobe unit.

[0249]FIGS. 38A and 38C show examples of a change in the brightness fromthe position of the main subject to the position of the background. Asdescribed above, when the photographic scene is underexposed, thebrightness difference ΔBV between the person, the main subject, and thebackground subject varies with the degree of underexposure. If the ΔBVis small, that is, if the photographic scene is as shown in FIG. 38A,the person and the background cannot be separated distinctly unless theminute change in the light quantity is emphasized. For this reason,correction is made by a γ conversion process with the characteristic asshown in FIG. 38B. In addition, contour emphasis may be made.

[0250] On the other hand, when a balance in brightness between thebackground and the person is clearly bad, a γ conversion process withthe characteristic as shown in FIG. 38D is carried out, becausecompressing the changed part to emphasize the bright part improves abalance between the background and the person.

[0251]FIG. 35 shows a flowchart for photographing control inbacklighting including switching control of the γ conversion process. Inthe flowchart, explanation will be given, provided that the photographicscene is against light. Explanation of the process of making a decisionon backlighting will be omitted.

[0252] First, the CPU 131 takes in an image with the imaging section 137(step S171). Then, the photographic lens 135 is focused (step S172). Thefocusing may be done by the method of either the 8th or 9th embodiment.In the tenth embodiment, the method of the second embodiment is used.

[0253] Next, the strobe light emission section 136 is caused to emitlight previously and the imaging section 137 takes in the image at thattime (step S173). Next, the exposure time that brings the backgroundsubject to the proper exposure level is calculated (step S174).Thereafter, the amount of emission of light by the strobe unit necessaryto bring the main subject to the proper exposure level is determined(step S175). Then, the brightness difference ΔBV between the mainsubject and the background subject is found (step S176).

[0254] Next, it is determined whether ΔBV is larger than a specificlevel (step S177). If ΔBV is equal to or less than the specific level,that is, if the photographic scene is as shown in FIG. 38A, setting isdone so as to carry out a γ conversion process with the characteristicof FIG. 38C to emphasize a change in ΔBV (step S178). Then, aftersetting is done so as to emphasize the contour near ΔBV (step S179),control proceeds to step S183.

[0255] On the other hand, if it has been determined in step S177 thatΔBV is larger than the specific level, that is, the photographic sceneis as shown in FIG. 38C, setting is done so as to carry out a γconversion process with the characteristic of FIG. 38D to weaken(compress) a change in ΔBV (step S180) Furthermore, setting is done soas to weaken the contour near ΔBV (step S181). In this case, the brightpart of the background can disappear in white. Therefore, after settingis done to emphasize the contour of the bright part (step S182), controlgoes to step S183.

[0256] After such operations, strobe photographing is done (step S183).Then, after the image is processed according to the above settings (stepS184), the resulting image is recorded into the recording section 142(step S185). After the image is recorded in the recording section 142,the backlight photographing control in the flowchart is completed.

[0257] As described above, with the tenth embodiment, the imageprocessing is effected automatically on the basis of the difference inbrightness between the background and the main subject duringbacklighting. This makes it possible to take a picture with a goodbalance in tone between the background and the subject.

[0258] Accordingly, with the present invention, it is possible toprovide a camera which is capable of producing a natural image accordingto the photographic scene and excels in snapshot capabilities. Thepresent invention is not limited to the above embodiments and may bepracticed or embodied in still other ways without departing from thespirit or essential character thereof.

What is claimed is:
 1. A camera comprising: a sensor array which detects an image signal of a subject existing in a specific position on a photographic screen and has a plurality of sensors; a computing section which calculates the average value of the outputs of a part of said plurality of sensors in the sensor array; an average photometric sensor which detects the average brightness at the photographic screen; an average luminance computing section which calculates the average luminance value at the photographic screen on the basis of the output of the average photometric sensor; a subject state judgment section which determines the state of the subject by comparing the average value of the sensor outputs with the average luminance value; and an exposure control determining section which determines exposure control during photographing on the basis of the average luminance value and the results of the determinations at the subject state judgment section and the subject field state judgment section.
 2. The camera according to claim 1, further comprising: a photographic optical system capable of variable power; a first optical system which directs light from the subject to the sensor array and is different from the photographic optical system; and a second optical system which directs the light from the subject to the average photometric sensor and is different from the photographic optical system, wherein the average photometric sensor has a plurality of light-receiving portion, each having a different light-receiving range, and changes not only the size occupied by a part of said plurality of sensors in the sensor array used in the computing section but also the light-receiving range of the average photometric sensor according to the variable power state of the photographic optical system.
 3. The camera according to claim 1, wherein the sensor array produces a distance-measuring image signal, and the outputs of a part of said plurality of sensors in the sensor array used in the computing section correspond to the sensor outputs used for distance measurement.
 4. The camera according to claim 3, further comprising: a photographic optical system; wherein the sensor array is capable of forming a distance-measuring image signal at a plurality of position on the photographic screen, and the outputs of a part of said plurality of sensors in the sensor array used in the computing section correspond to the outputs of the sensors used to output distance data used to focus the photographic optical system among a plurality of positions on the photographic screen.
 5. The camera according to claim 1, further comprising: a strobe unit which emits strobe light toward the subject; and a judgment section which determines whether the strobe light reaches the subject, wherein the exposure control determining section determines exposure control during photographing, taking into account the result of the determination at the judgment section.
 6. The camera according to claim 5, wherein the exposure control determining section determines exposure control during photographing so as to cause the strobe unit to emit light and perform exposure control, when the judgment section has determined that the strobe light reaches the subject and the result of the determination at the subject state judgment section has shown a specific state.
 7. The camera according to claim 6, wherein the subject state judgment section determines whether the subject is against light, and the specific state is a state where the subject is against light.
 8. The camera according to claim 5, further comprising a discriminative section which discriminates the mode of the camera, wherein the exposure control determining section determines exposure control during photographing, taking into account the result of the result of the discrimination at the discriminative section.
 9. A camera comprising: a photographic optical system; an area sensor which outputs a first image signal, the first image signal being an image signal of a subject detected via the photographic optical system; an optical system different from the photographic optical system; and a sensor which outputs a second image signal, the second image signal being an image signal of the subject detected via the optical system different from the photographic optical system, wherein a distance is detected from the second image signal and a part of the first image signal, which coincides with a viewing range of the area sensor.
 10. A camera comprising: a sensor array which detects an image signal of a subject existing in a specific position on a photographic screen and has a plurality of sensors; a computing section which calculates the average value of the outputs of a part of said plurality of sensors in the sensor array; an average photometric sensor which detects the average brightness of visible light at the photographic screen; an average luminance computing section which calculates the average luminance value at the photographic screen on the basis of the output of the average photometric sensor; an infrared photometric sensor which detects an infrared luminance value indicating the brightness of the average infrared light at the photographic screen; a subject state judgment section which determines the state of the subject by comparing the average value of the sensor outputs with the average luminance value; a subject field state judgment section which determines the state of a subject field including the subject by comparing the average luminance value with the infrared luminance value; and an exposure control determining section which determines exposure control during photographing on the basis of the average luminance value and the results of the determinations at the subject state judgment section and the subject field state judgment section.
 11. The camera according to claim 10, further comprising: a strobe unit which emits strobe light toward the subject; and a judgment section which determine whether the strobe light reaches the subject, wherein the exposure control determining section not only determines exposure control during photographing so as to cause the strobe unit to emit light and perform exposure control, when the judgment section determines that the strobe light reaches the subject and the result of the determination at the subject state judgment section has shown a specific state, but also determines exposure control during photographing so as to cause the strobe unit to emit light and perform exposure control, when the judgment section determines that the strobe light reaches the subject and the result of the determination at the subject field state judgment section has shown a specific state.
 12. The camera-according to claim 11, wherein the subject state judgment section determines whether the subject is against light, and the specific state is a state where the subject is against light.
 13. The camera according to claim 11, wherein the subject field state judgment section determines whether the light source of the subject field is artificial, and the specific state is a state where the light source of the subject field is artificial.
 14. The camera according to claim 11, further comprising a discriminative section which discriminates the mode of the camera, wherein the subject state judgment section does not make a decision, when the discriminative section has determined that the camera is in a specific mode.
 15. The camera according to claim 14, wherein the specific mode is at least one of a strobe OFF mode, a spot photometric mode, and an infinite photographic mode.
 16. The camera according to claim 11, further comprising a discriminative section which discriminates the mode of the camera, wherein the subject field state judgment section does not make a decision, when the discriminative section has determined that the camera is in a specific mode.
 17. The camera according to claim 16, wherein the specific mode is at least one of a strobe OFF mode, a spot photometric mode, and an infinite photographic mode.
 18. The camera according to claim 10, further comprising: a photographic optical system; and a finder which is provided separately from the photographic optical system and is for viewing the image of the subject, wherein the sensor array and the average photometric sensor are provided near the finder.
 19. The camera according to claim 18, wherein the infrared photometric sensor is provided farther away from the finder than from the average photometric sensor and sensor array.
 20. A camera comprising: a photometric section which measures the subject luminance in a plurality of areas on a photographic screen; a distance-measuring section which measures the subject distance in a plurality of areas on the photographic screen; a first select section which selects one from a plurality of distance-measuring areas on the photographic screen on the basis of the distance-measuring data about each distance-measuring area; a second select section which selects one from the photometric area corresponding to the distance-measuring area selected by the first select section and its adjacent photometric areas on the basis of the photometric data about each photometric area; and a backlight judgment section which makes a decision on backlighting by comparing the photometric data about the photometric area selected by the second select section with the photometric data about each photometric area.
 21. The camera according to claim 20, wherein the distance-measuring area selected by the first select section is the distance-measuring area whose distance-measuring data indicates the closest distance.
 22. The camera according to claim 20, wherein the photometric area selected by the second select section is the photometric area whose photometric data indicates the lowest luminance.
 23. The camera according to claim 20, wherein the photometric section and the distance-measuring section share a light-receiving section.
 24. A camera comprising: a photometric section which measures the subject luminance in a plurality of areas on a photographic screen; a distance-measuring section which measures the subject distance and subject luminance in a plurality of areas on the photographic screen; a first select section which selects one from a plurality of distance-measuring areas on the photographic screen on the basis of the distance-measuring data about each distance-measuring area; a second select section which selects one from the distance-measuring area selected by the first select section and its adjacent distance-measuring areas on the basis of the photometric data about each distance-measuring area; and a backlight judgment section which makes a decision on backlighting by comparing the photometric data about the distance-measuring area selected by the second select section with the photometric data from the photometric section.
 25. The camera according to claim 24, wherein the distance-measuring area selected by the first select section is the distance-measuring area whose distance-measuring data indicates the closest distance.
 26. The camera according to claim 24, wherein the distance-measuring area selected by the second select section is the distance-measuring area whose distance-measuring data indicates the lowest luminance.
 27. The camera according to claim 24, wherein the photometric section and the distance-measuring section share a light-receiving section.
 28. A camera comprising: an imaging section which detects a subject image signal; a backlighting state judgment section which determines whether the subject is against light; a strobe unit which emits strobe light onto the subject on the basis of the result of the decision on backlighting at the backlighting state judgment section; and an image processing section which compares the brightness of the subject with that of the background when the strobe unit emits the strobe light onto the subject, changes the amount of correction by a gamma conversion process or a contour emphasizing process on the basis of the result of the comparison, and processes the image of the subject image signal detected by the imaging section.
 29. The camera according to claim 28, further comprising: a subject distance judgment section which determines the distance to the subject, wherein it is determined whether the strobe light has a sufficient light quantity for the subject, on the basis of the subject distance determined by the subject distance judgment section, and when the result has shown that the strobe light has a sufficient light quantity and the exposure value of the background is larger than a specific value, the image processing section increases the gamma value in the gamma conversion process and processes the image so as to weaken contour emphasis in the contour emphasizing process.
 30. The camera according to claim 28, further comprising: a subject distance judgment section which determines the distance to the subject, wherein it is determined whether the strobe light has a sufficient light quantity for the subject, on the basis of the subject distance determined by the subject distance judgment section, and when the result has shown that the strobe light has a sufficient light quantity and the exposure value of the background is less than a specific value, the image processing section does not change the amount of correction in the gamma conversion process and the contour emphasizing process.
 31. The camera according to claim 28, further comprising: a subject distance judgment section which determines the distance to the subject, wherein it is determined whether the strobe light has a sufficient light quantity for the subject, on the basis of the subject distance determined by the subject distance judgment section, and when the result has shown that the light quantity is insufficient and the insufficient quantity is larger than a specific quantity, exposure is made so as to increase the exposure value.
 32. The camera according to claim 28, further comprising: a subject distance judgment section which determines the distance to the subject, wherein it is determined whether the strobe light has a sufficient light quantity for the subject, on the basis of the subject distance determined by the subject distance judgment section, and when the-result has shown that the light quantity is insufficient and the insufficient quantity is smaller than a specific quantity, the image processing section increases the gamma value in the gamma conversion process and makes a correction so as to weaken contour emphasis in the contour emphasizing process.
 33. A camera comprising: an imaging section which detects a subject image signal; a distance-measuring section which measures the distance to the subject; a strobe unit whose light quantity is controlled on the basis of the result of the distance measurement at the distance-measuring section; an image processing section which processes the subject image signal detected by the image processing section; an illumination state judgment section which determines the illuminated state of the subject before photographing; and a control section which controls the strobe unit and the image processing section on the basis of the result of the output of the distance-measuring section and the result of the output of the illumination state judgment section. 